1. Field of the Invention
The present invention relates to a haymaking machine, particularly for windrowing forage, comprising a frame carrying several windrowing rotors which can be driven in rotation about substantially vertical support axes, which rotors are connected to carrier arms which are articulated to the frame by means of articulation axes about which they can be moved from a substantially horizontal work position into a substantially vertical transport position and vice versa, said carrier arms being made as two telescopic parts of which the first is connected to the axis of articulation on the frame and the second carries the corresponding rotor, it being possible for this second part to slide with respect to said first part in order to vary the position of the corresponding rotor with respect to the frame between an inner position in which its support axis is located a minimum distance from the articulation axis of the corresponding carrier arm and an outer position in which its support axis is located a maximum distance from said articulation axis.
2. Discussion of the Background
A known machine of this kind comprises four rotors arranged in such a way as to form a first pair which is situated toward the front of the frame and a second pair which is situated toward the rear of the frame. In the work position, these rotors form a V and gather the forage together into a central windrow. The maximum working width is achieved when the telescopic parts of the carrier arms are entirely deployed to bring the rotors into their outer positions. This maximum working width depends on the travel of the second parts of the telescopic arms which carry the rotors situated toward the front of the frame. Said travel is, however, limited by the fact that, in the deployed position, it is necessary to maintain a correct overlap between the first and the second telescopic parts of the carrier arms and by the fact that the length of said parts is also limited in order not, in the transport position, to exceed the permitted height for travel on the public highway.
The maximum working width which can thus be obtained with this known machine is not sufficient to form, in a single pass, a windrow the volume of which is suited to the great processing capacity of machines such as the self-propelled forage harvesters currently available.
In another known machine, each arm carrying one of the rotors of the first pair is mounted on an additional chassis. The latter can be moved laterally on the main frame of the machine with a view to being able to increase the maximum working width. Such a construction makes the machine considerably more complicated and considerably more expensive.
It is an object of the present invention to overcome the aforementioned drawbacks of the known machines. The invention has in particular to propose a machine that makes it possible, in a simple way, to obtain a very wide working width.
To this end, a significant feature of the invention consists in the fact that the first telescopic part of at least each arm carrying one of the rotors of the first pair comprises an additional guide section which extends in its continuation beyond the support axis of the corresponding rotor when the latter is located in the inner position and the length of which is such that it allows the second telescopic part to be guided as far as an outer position in which the value of the distance from the support axis of the rotor to the axis of articulation of the corresponding carrier arm is substantially twice the value of this distance when the rotor is in said inner position.
This arrangement makes it possible in a simple way to double the working width of the machine by moving it from the minimum position to the maximum position. In the latter position, the machine can produce windrows of very large volume on each pass. Furthermore, when placed in the transport position, the carrier arms can maintain the length they have in the minimum position. The height thus achieved with these arms remains within the limits allowed for transport.